"Could not find the icon 'object-visible-ltr'" warnings with trunk build, Windows 10

Reproduced with latest devlibs64 and lp:inkscape r15534 on Windows 10.

Probably a packaging issue with GTK3 on Windows ('share\icons\hicolor\index.theme' file missing in devlibs64).

Fixed in r15535
http://bazaar.launchpad.net/~inkscape.dev/inkscape/trunk/revision/15535

(Already had that change in my repo but forgot to commit/push it...)

Reincarnation of bug #1635207 btw.

@Eduard - any specific reason why the real index.theme file from the hicolor icon theme is not installed for GTK3-based trunk builds, and instead a empty one is created?

I tested it with devlibs64 trunk build and with your MSYS2 build: adding the hicolor/index.theme file from a different installation [1] to the hicolor icon theme does not seem to have negative side effects, and it allows Inkscape trunk to find (and use) the deprecated but still provided internal stock icon for 'gtk-preferences'. With the empty place-holder index.theme file, the button for Inkscape's preferences on the command controls bar renders with the 'image-missing' icon (also mentioned in my earlier comment in bug #1638353, though at the time I wrote that comment I was not aware that the compiled-in (deprecated) stock icons apparently are not available in Windows trunk builds due to the missing information from the hicolor/index.theme file)

[1] hicolor index.theme file used for testing:
    https://gist.github.com/su-v/07dd9d0ee843aa6a482846b6afaeace8
    For the tests, I also removed (renamed) an existing icon-theme.cache
    file that might exist in share\icons\hicolor\

> any specific reason why the real index.theme file from the hicolor icon theme is not installed for GTK3-based trunk builds, and instead a empty one is created?

Specific reason: Yes
I simply put in the fix from 0.92.x. As there is no "/share/icons/hicolor" in devlibs someone started to use an empty index.theme at some point. As this caused crashes with devlibs64 I added a dummy file which worked fine for both.

Good reason: No
You're completely right that we could include the correct file instead of using a dummy, especially if it causes stock icons to break (I wasn't aware of such an issue).
Do you know if we have to install all the empty folders too, or can we safely omit them and only install the index.theme?

Eduard Braun wrote:
> Do you know if we have to install all the empty folders too, or can
> we safely omit them and only install the index.theme?

As far as I understand it's save to omit them (as long as any missing (sub-)directories are created when installing Inkscape - check cmake's install_manifest.txt). Depending on what (else) was installed in the current prefix, they might not all be empty, anyway:
<quote>
In order to have a place for third party applications to install their icons there should always exist a theme called "hicolor" [1]. The data for the hicolor theme is available for download at: http://www.freedesktop.org/software/icon-theme/. Implementations are required to look in the "hicolor" theme if an icon was not found in the current theme.
</quote>
https://standards.freedesktop.org/icon-theme-spec/icon-theme-spec-latest.html#directory_layout

@su_v: For MSYS2 builds we now install the correct index.theme, see
http://bazaar.launchpad.net/~inkscape.dev/inkscape/trunk/revision/15581